Transformer switch with snap action operator



Jan. 5,1965 J. H. NICHOLAS ETAL 3,164,593

' TRANSFORMER SWITCH WITH SNAP ACTION OPERATOR 5 Sheets-She'et 1 Filed May 10, 1961 zwmrona Jzzzrza JiMc/zo if I m5 ifig gwmm Jan. 5, 1965 J. H. NICHOLAS ETAL 3, 93

TRANSFORMER SWITCH WITH SNAP ACTION OPERATOR Filed May 10. 1961 5 Sheets-Sheet 2 J. H. NICHOLAS ETAL TRANSFORMER SWITCH WITH SNAP ACTION OPERATOR 5 Sheets-Sheet 3 Jan. 5, 1965 Filed May 10, 1961 W Maw 4 Jan. 5, 1965 J. H. NICHOLAS ETAL 3,164,693

TRANSFORMER swncn wrm SNAP ACTION OPERATOR Filed May 10. 1961 L95/0/&99:77 a 97 9,80 m

5 Sheets-Sheet 4 66-- 0| m Q1} I Jan. 5, 1965 J. H. NICHOLAS ETAL 3,154,693

TRANSFORMER SWITCH WITH SNAP ACTION OPERATOR Filed May 10, 1961 5 Sheets-Sheet 5 660/ e z 8109010450 g/ United States Patent The invention relates to switch mechanism and has reference in particularto switch mechanism of the singlepole double-break type having toggle structure for snap action operation.

The basic structure of the present switch consists of two stationary contacts secured respectively to fixed insulators, with a third insulator positioned between and being rotatable for actuating a switch blade. The rotary insulator is operatively connected to toggle mechanism for snap action operation whereby the rotary insulator and the switch blade are given rapid movement for making and breaking an electric circuit at the stationary contacts.

Oil filled transformers such as those of the pad mounted type require switch structure such as described, but which need not be elaborate nor complicated indesign, since relatively few operations are demanded of the switch mechanism during the uset'ul life of the transformer. The present switch has been primarily designed to fulfill such needs, and accordingly simplicity in construction embodying relatively few parts but with emphasis on stui-dines's and'efficiency in operation have been the paramount considerations. 7

Another object of the invention resides in the provision of a single-pole, double-break switch having a toggle device in connected relation with the actuating shaft for producing snap-action operation of the rotatable switch blade for a rapid separation of the blade from the stationary contacts on an opening action of the switch.

Since the switch blade of the present mechanism may remain in engagement with the stationary contacts for a long period of time, on the order of a year or more, it is possible for frictional resistance to develop such as might freeze the contacts and prevent opening of the switch by the action of the toggle device. To prevent such failures in operation, the invention contemplates a camming action on the switch blade to be produced by the operating shaft for effecting initial movement of the blade in an opening direction, whereby to overcome said frictional resistance and insure proper operation.

In View 'of the foregoing a more specificiobject is to provide 'switch'mechanism as described which will incorporate a camming lever adapted to be actuated by the operating shaftwhen the shaft'is rotated in a direction for opening the switch and which will produce initial movement of the switch blade immediately in advance of the action of the toggle device and which will thus assist the toggle device in rotating the switch blade for breaking the electric circuit.

With these and various other objects in view the invention may consist of certain novel features of construction and operation, as will be morefully described and particularly pointed out in the specification, drawings and claims appended thereto. I

In the drawings which illustrate an embodiment of the device and wherein like reference characters are used to designate like parts V FIGURE 1 is a plan elevational view of a preferred embodiment of switch mechanism for transformer use and which incorporates the toggle device and camming means of the invention;

FIGURE 2 is a front elevational view of the switch 3,164,693 Patented Jan. 5, 1965 assume when the switch blade is closed;

FIGURE 4 is a rear elevational view similar to FIG- URE 3 but illustrating the action of the camming lever as the toggle device is moved from a dead center position in a switch opening direction; a V 1 FIGURE 5 is a rear'elevational view similar to FIG- URE 4 but showing the position the parts assume when the switch blade is open;

FIGURE 6 is a detail view of the rotatable insulator with parts being shown in section for illustrating the connection of the operating shaft thereto;

FIGURE 7 is a. plan elevational view of another embodiment of switch structure' corningwithin the invention;

FIGURE 8 is a sectional view taken substantially along line 8-8 of FIGURE 7;

FIGURE 9 is a sectional view taken transversely through the central insulator substantially along line 99 of FIGURE 7; and

FIGURE 10 is a sectional view taken substantially along line 10-10 of FIGURE 7.

The preferred embodiment of the invention as shown in FIGURES l and 2 essentially consists of a metal frame or mounting bracket 10, to which is secured a pair of stationary insulators 11 and 12 by the screws 13, the said screws entering the insulators from the rear of the mounting bracket 10. The front surface of the insulators 11 and 12 have secured thereto the contacts 14 and 15, which are provided with entrance openings 16 and which are secured to the insulators, respectively, by the screws 17. As best shown in FIGURE 2, the entrance opening 16 of stationary contact 14 projects upwardly in a diagonal right-hand direction, whereas the entrance opening 16 of stationary contact 15 e xtends downwardly in a left-hand direction. A metal spacing plate 18 may be interposed between the frame and the insulators and a similar spacing plate 19 may be interposed between the insulators and the stationary contacts.

The third insulator 20 of the switch mechanism is mounted by the operating shaft 21 for rotation and the insulator 20 carries at its front end the switch blade 22 which is secured to the insulator by the screws 23. A

-- metal spacer 24 may be interposed between the switch blade and the insulator. By referring to FIGURE 6 it will be seen that shaft 21 has a head 25 formed integral therewith, and which is positioned between the end of the insulator and the flanged disc 26. A pair of screws 27 C securely fasten the disc 26 to the insulator 26 with the spacer 28 being interposed between the parts. The structure unites shaft 21 and the insulator 21) so as to provide an assembly and wherein shaft 21 and insulator 20 may have rotation independently of each other.

The numeral 30 indicates the actuating lever of the toggle device and which is fixed to shaft 21 by the U shaped terminal end 31 and the pin 32. A flexible metal washer 33 is located between the frame 10 and the terminal end 31 of the actuating lever in order to take up i any excessive play or looseness between the parts. The

opposite end of the actuating lever 3t) is flanged as at 34 and the said flange is apertured at 35 for receiving the rod 36 of the toggle device. The other end of rod 36 is formed to provide the eye 37, FIGURES 3, 4 and 5, and

' which has engagement with the pin 38 fixed to the flanged disc 26. The toggle device is completed by the coil spring 40 having encircling relation with the rod 36 and which is confined between the eye 37 at one end and the flange 34 at its opposite outer end. i

The rod 36 and the actuating lever 39 accordingly have rotative movements about different axes although the rod and the lever are united at the flanged end 34 of the lever. A toggle device is thus provided and which is operative to cause snap-action operation of the flanged disc 26, and thus similar action of the switch blade 22 connected thereto, as the operating shaft 21 is oscillated. The frame it is recessed at 41 along the top edge approximately centrally of the frame for accommodating the pin 38 and which moves from one end of the recess 41 to, the other as the toggle device is actuated, withthe ends of the recess, namely 42 and 43 providing stops limiting themovement of the pin 'in'the direction of the stops, respectively. A dead center position of the toggle device exists when a straight line includes'the rod 56,.the pin 3?, and the actuating shaft 21. 'Thus a dead center position will exist when the actuating lever 3t3 is oscillated in either direction. However, to'cause oscillating movement of the disc 26 and switch blade 22, the actuating lever 30 7 FIGURE 3, then toeifect an opening of the switch, the

actuating shaftiZl is rotated in a clockwise direction which will effect similar rotation of the actuating lever 36, it being observed that the pin 38 is located in a right-hand position adjacent stop 42. The oscillating movement of lever 39 will compress the coil spring 4%? and as the lever or mounting bracket 6t has suitably secured thereto the though the cam 48' has full camming engagement with lever 45', nevertheless the said lever is free as regards the pin'38. Also, on returning movement of the operating shaft 21 and actuating lever 3d, a camming of the lever 45 for a portion of the movement will take place, but eventually the cam 48 will move out of contact with the lever. This takes place at or about dead center position so that'when snap action of the toggle device occurs for closing the contacts, the camming lever 45 is inoperatively positioned so that it does not interfere with the closing action of the switch in any wayiwhatsoever.

In the modification of FTGURES 9 and 10 the frame fixed insulators 61 and 62, andfeach insulator is in turn connected at their front end by the frame element 63. Each fixed insulator has a stationary contact secured thereto, contact 64 being-secured to insulator 61 by the strap member 66 whereas contact 65is-secured to insulator 62 by the strap member 67. The strap member 66 is located centrally of the length of the insulator 61 and the said member is tightened by the screw and nut combination 68. The head of the rivet 7i) is located in the arcuate depression 71which thus properly positions the contact 64 passes beyond dead center as shown in FIGURE 4, the

compressive force of the spring is released to cause movea switch blade 22 as thus effected will cause the ends of the blade to separate from the respective stationary contacts 14 and 15 to thus open the switch. a

This snap-action with rapid separation of the blade from the contacts is desired inorder to prevent excessive arcing. Also, the toggle device relieves the operator of actually separating and engaging the switch contacts, since after a dead center position of the toggle device has been reached, the said toggle device takes over and produces the necessary oscillation of the parts for opening and closing the switch, all independent of any further action on the part of the operator.

When the present switch is employed in combination with transformer structure, his not unusual for the switch to remain in closed circuit position for a long period. of time, probably for a year or more.- Thus, frictional resistance can develop between the switch blade and the stationary contacts freezing the parts and preventing opening action of the switch by the toggle device. To prevent such an occurrence, the invention contemplates the provision of a camming lever 45, pivoted at 46 adjacent the rear surface of the frame 10. The lever has a camming portion 47 disposed in operative association with the pin 38 and located between the eyelet 37 and the frame 10. The actuating lever is provided with the same 48 which, however, is adapted to have camming action with the lever 45 during a portion only of the oscillating movement of theshaft, and then only for an opening action ofthe switch. The camming action of lever 45 is transmitted to the pin 38 by the portion 47 and the same is so arranged and so timed as to effect movement of the pin and thus movement of the switch blade 22 immediately in advance of the action of the toggle device in an opening direction. I

With the switch blade 22 in open position the parts assume the position as shown in FIGURE 5. The actuating lever 30 is located in right-hand position with the pin 33 in left-hand position in contact with stop 43. Al-

in an upward direction and slightly inclined toward the center of the frame 66. The strap member 67 is similarly fixed centrally of the insulator 62, being tightened by the screw and nut combination 72, and being properly positioned with contact 65 extending downwardly and inwardly, since the head of the rivet 73 rests in the arcuate depression 74. i

The third insulator of the switch is indicatedby numeral 76 and thisinsulator is journalled for rotation by the operating shaft 77 as best shown'in FIGURE 9. For this purpose the frame 6t? and frame element d3 are bent outwardly to a slightextent approximately centrally of the frame parts, and metal spacing washers 78 and 80 are interposed between each frame part and its respective end of the insulator 76. The washer 73 at the front end of the insulator has a plurality of bent clips or flanges 82 in contact with the peripheral surface at this end of the insulator. The washer 80 at the rear of the insulator is likewise provided with a plurality of clips or flanges 83 and in accordance with the invention the same fit into grooves 84 formed in the peripheral surface at the rear end of the insulator. The washer St) is accordingly locked to the insulator 76 and rotative movements imparted to the washer Will thus be transferred to the insulator.

' The center rotatable insulator 7 6 carries the switch blade 85 and which is secured thereto substantially centrally the length of the insulator by the strap member 86. The upper part of the switch blade 85 is secured to the strap member by the rivets 8'7 with the lower part of the blade being secured to said strap member by'therivets 88, such structure being clearly shown in FIGURE 9. The headfof each rivet rests in a depression or arcuate recess such as 89 for properly positioning and holding the switch blade to the insulator. Conventional structure such as the screw and nut combination 90 is employed for tightening the strap member 86. The switch blade 85 and the stationary contacts 64 and 65, are each secured to their insulator in substantial alignment whereby oscillating movement imparted to the rotatable insulator 76 will effect coaction of the switch blade with the stationary contacts for opening and closing an elecric circuit.

The desired rotative movement of the switch blade 85 is effected by a toggle device having connecting relation with the pin 91 which is fixed to the washer 80 so as to project rearwardly from said washer. To accommodate the pin the top edge of the frame 60 is recessed at 92, FIGURE 10; and the edges of said recess provide stops 93 and 94 which limit movement of the pin in their respective directions. The actuating lever 95 of the toggle device is fixed to the operating shaft 77 by the pin 96 and the outer end of the actuatinglever is flanged as at 97. The flange 97 is apertured'forreceiving the end of the rod 98 which is formed with the eyelet 100 having connecting relation with the pin 91. The coil spring 101 has encircling relation with the rod 98 and the same is confined between the eyelet and the flanged end 97 of the actuating lever.

The operation of the switch mechanism as shown in FIGURES 7 to 10, inclusive, is substantially the same as described with respect to the preferred modification. With the switch blade 85in open position as shown, it will be observed that the pin 91 is located at the left, FIGURE 1Q, in contact with stop 93. To close the switch the operating shaft 77 is rotated in a clockwise direction, FIGURE 8, and when dead center position is reached as regards the toggle device, a straight line will include the rod 98, the pin 91, and the shaft 77. Further movement of the operating shaft and thus the lever 95 in a clockwise direction will locate the parts beyond dead center in which position the full compressive force of the coil spring 101 is exerted on the pin 91 causing the same to move with snap action to the opposite end of the recess in contact with stop 94. The resulting oscillating movement of the washer 80 is accordingly imparted to the rotatable insulator 76 and to the switch blade 85 whereby to effect a closingvof the switch. Reverse action of the parts for opening the switch takes place in a similar manner. The snap action as effected by the toggle device produces such a rapid separation of the switch blade from the contacts as to substantially prevent arcing. 1

'The invention is not to be limited to or by details of construction of the particular embodiment thereof illustrated by the drawings, as various other forms of the.

device will, of course, be apparent to those skilled in the art without departing from the spirit of the invention or the scope of the claims.

What is claimed is: a

1. In switch mechanism of the character described, the combination with a mounting bracket, of a pair of insulators fixed to the bracket in spaced relation, a stationary contact carried by each insulator, a third insulator located between the fixed insulators, a shaft mounting the third insulator on the bracket for rotation, a switch blade fixed to the third insulator in alignment with the stationary contacts for coaction therewith, said stationary contacts having contact surfaces perpendicularly disposed to theaxis of rotation of the third insulator, a pin extending from the third insulator and disposed substantially parallel to the axis of said insulator, and toggle means in associated relation with and having operative contact with the pin and with said shaft for effecting oscillating movements of the third insulator whereby to cause the switch blade to coact with the stationary contacts.

' 2. In switch mechanism of the character described, the,

combination with a mounting bracket, of a pair of insulators fixed to the bracket in spaced relation, a stationary contact carried by each insulator, a third insulator located between the fixed insulators, a switch blade fixed to the third insulator in alignment with the stationary contacts for coaction therewith, an operating shaft mounting the third insulator on the bracket for rotation, said stationary contacts having contact surfaces perpendicularly disposed to the axis of rotation of the third insulator, a pin extending from the third insulator, and a toggle device in associated relation with the operating shaft and with the pin, said device-including an actuating lever fixed to the shaft, a rod connecting with the'pin at one end and with the actuating lever at its opposite end, and a coil spring having encircling relation with the rod and being confined between the pin and the lever where the lever connects with the rod, said toggle device, when actuated, effecting oscillating movement of the third insulator to cause the switch blade to coact with the stationary contacts.

3. In switch mechanism of the character described, the combination with a mounting bracket, of a'pair of insulators fixed to the bracket in spaced relation, a stationary contact carried by each insulator, a third insulator located between the fixed insulators, a switch blade fixed to the third insulator in alignment with the stationary contacts for coaction therewith, an operating shaft mounting the third insulator on the bracket for rotative movements, said insulating contacts having contact surfaces perpendicularly disposed to the axis of rotation of the third insulator, a pin extending from the third insulator and disposed substantially parallel to the axis of said insulator, stop means for thepin having spaced relation whereby movement of the pin and thus oscillating movement of the third insulator is limited by said means, and toggle means having associated relation with, and having operative contact with, the shaft and with the pin for effecting said oscillating movements of the third insulator whereby to cause the switch blade to coact with the stationary contacts.

4. Switch mechanism as defined by claim 3, wherein said toggle means includes an actuating lever fixed to the operating shaft, a rod having an eyelet at one end in engagement with the pin and having its other end connecting with the actuating lever, and a coil spring encirto the axis of rotation of the third insulator, a switch blade fixed to the third insulator in alignment with the stationary contacts for coaction therewith, toggle means for producing movement of the third insulator and the switch blade with snap action for rapidly making and breaking an electric circuit connecting with the stationary contacts, and camming means adapted to be cammed by rotation of the operating shaft in a switch opening direction for effecting initial opening movement of the switch blade immediately in advance of action by the toggle means to also cause movement of the switch blade in an opening direction.

6. In switch mechanism of the character described, the combination with a mounting bracket, of a pair of spaced insulators fixed to the bracket, a stationary contact carried by each insulator, a third insulator located between the fixed insulators, an operating shaft and which mounts the third insulator on the bracket for rotation, said stationary contacts-having contact surfaces perpendicularly disposed to the axis of rotation of the third insulator, a switch blade fixed to the third insulator in alignment with the stationary contacts for coaction therewith, toggle means including a lever fixed to the operating shaft, a rod connecting the lever with the third insulator and a coil spring having encircling relation with and being mounted on the rod for producing movement of the third insulator as the toggle means is actuated whereby to cause the switch blade to coact with the stationary contacs, and camming means adapted to be cammed by rotation of the operating shaft in a switch opening direction for effecting initial opening movement of the switch blade immediately in advance of action by the toggle means to cause movement of the switch blade in the same direction.

7. In switch mechanism of the character described, the combination with a mounting bracket, of a pair of spaced insulators fixed to the bracket, a stationary contact carried by each insulator, a third insulator located between the fixed insulators, an operating shaft and which mounts the third insulator on the bracket for rotation, said stationary contacts having contact surfaces perpendicularly disposed to the axis of rotation of the third insulator, a switch blade fixed to the third insulator in alignment with the stationary contacts for coaction therewith, a pin extending from the third'insulator and disposed parwith the operating shaft and with the pin and operative toproduce movement of the third insulator and The switch blade with snap action for rapidly making and breaking an electric circuit connection with the stationary contacts, a cam fixed to the operating shaft, and a camrning lever pivoted to the bracket andhaving a portion adapted to engage the pin, said lever being actuated by the cam uponrotation of the operating shaft in a switch opening directionwhereby the lever iscaused to earn the pin and effect initial opening movement of the switch blade, said cam and lever being so constructed and arranged that the camrning of the pin takes place immediately in advance of action by the toggle means to cause movement of the switch blade in a switch opening 5 direction.

7 Reterences'fiitedin the file of this patent UNITED STATES PATENTS Sachs -.--V-'v May 28, 1935 Viets Nov. 2,, 1920 

1. IN SWITCH MECHANISM OF THE CHARACTER DESCRIBED, THE COMBINATION WITH A MOUNTING BRACKET, OF A PAIR OF INSULATORS FIXED TO THE BRACKET IN SPACED RELATION, A STATIONARY CONTACT CARRIED BY EACH INSULATOR, A THIRD INSULATOR LOCATED BETWEEN THE FIXED INSULATORS, A SHAFT MOUNTING THE THIRD INSULATOR ON THE BRACKET FOR ROTATION, A SWITCH BLADE FIXED TO THE THIRD INSULATOR IN ALIGNMENT WITH THE STATIONARY CONTACTS FOR COACTION THEREWITH, SAID STATIONARY CONTACTS HAVING CONTACT SURFACES PERPENDICULARLY DISPOSED TO THE AXIS OF ROTATION OF THE THIRD INSULATOR, A PIN EXTENDING FORM THE THIRD INSULATOR AND DISPOSED SUBSTANTIALLY PARALLEL TO THE AXIS OF SAID INSULATOR, AND TOGGLE MEANS IN ASSOCIATED RELATION WITH AND HAVING OPERATIVE CONTACT WITH THE PIN AND WITH SAID SHAFT FOR EFFECTING OSCILLATING MOVEMENTS OF THE THIRD INSULATOR WHEREBY TO CAUSE THE SWITCH BLADE TO COACT WITH THE STATIONARY CONTACTS. 